Training Quality-What Is It and How Can We Improve It?

The development of physical characteristics in adolescent team sport athletes: A systematic review

BACKGROUND

Physical development during adolescence is crucial for athletes in team sports, as it prepares them for the high sport demands at the senior level. While physical development in non-athletes are well-documented, a comprehensive understanding of adolescent athletes' development, including the potential effects of team sports participation and training load, is lacking.

OBJECTIVES

The study aimed to investigate the development of physical characteristics in team sport athletes during adolescence (12-20 years) and explore the impact of training load.

METHODS

A systematic search of the databases PubMed, SPORTDiscus and Web of Science were conducted combining keywords related to physical characteristics, youth athletes, team sport and study design. Criteria for inclusion were: (1) team sport athletes aged 12-20 years, (2) cross-sectional or longitudinal designs investigating physical characteristics, (3) comparisons across different age groups, (4) peer-reviewed original article, (5) written in English, and (6) available results from physical testing. Results were normalized and weighted based on sample size.

RESULTS

176 eligible articles were identified. The results showed consistent annual improvement in most physical characteristics from 12 to 16 years for both sexes (e.g., boys: lower body strength 14.3%; intermittent endurance 11%; countermovement jump height 6.7%; change of direction 2.8%; 30 m sprint 3.6%, and girls: lower body strength 9.4%; intermittent endurance 12.1%; countermovement jump 4.7%; change of direction 3.3%; 30 m sprint 1.9%). Only 4 studies investigated the effect of training load on physical development.

CONCLUSIONS

Although both sexes consistently improved through adolescence, girls tended to have less pronounced physical development compared to boys, likely due to lower increase in lean mass and limb length. The existing evidence do not definitively establish whether team sports participation, compared to studies examining non-athletes, or training load have an additive effect on physical development during this period.

From Incremental Test to Continuous Running at Fixed Lactate Thresholds: Individual Responses on %VO2max, %HRmax, Lactate Accumulation, and RPE

With Norway's successes in middle and long-distance running, lactate-guided threshold training has regained importance in recent years. Therefore, the aim of the present study was to investigate the individual responses on common monitoring parameters based on a lactate-guided conventional training method. In total, 15 trained runners (10 males, 5 females; 18.6 ± 3.3 years; VO2max: 59.3 ± 5.9 mL kg-1 min-1) completed a 40-min continuous running session at a fixed lactate threshold load of 2 mmol L-1. Lactate (La), oxygen uptake (VO2), heart rate (HR), and rating of perceived exertion (RPE) were recorded. The chosen workload led to lactate values of 2.85 ± 0.56 mmol L-1 (range: 1.90-3.80), a percentage of VO2max utilization (%VO2max) of 79.2 ± 2.5% (range: 74.9-83.8), a percentage of HRmax utilization (%HRmax) of 92.2 ± 2.5% (range: 88.1-95.3), and an RPE of 6.1 ± 1.9 (range: 3-10) at the end of the running session. Thereby, the individual responses differed considerably. These results indicate that a conventional continuous training method based on a fixed lactate threshold can lead to different individual responses, potentially resulting in various physiological impacts. Moreover, correlation analyses suggest that athletes with higher lactate threshold performance levels must choose their intensity in continuous training methods more conservatively (lower percentage intensity based on a fixed threshold) to avoid eliciting excessively strong metabolic responses.

Long-term development of performance, physiological, and training characteristics in a world-class female biathlete

Purpose

The purpose of this study is to investigate the long-term development of performance, physiological, and training characteristics in a world-class female biathlete, with emphasis on differences between junior and senior athlete seasons.

Methods

The participant is a highly decorated female biathlete with 22 (10 gold) medals from international championships and 28 individual World Cup wins. Performance development (ages 17-33), physiological tests (ages 22-33), and day-to-day physical and shooting training (ages 17-33) were analyzed. Training data were systemized by endurance [low-intensity training (LIT), moderate-intensity training (MIT), and high-intensity training (HIT)], exercise mode, and strength training. Shooting training recorded for each session included the number of shots fired during rest, LIT, MIT, HIT, or competitions and time spent on dry fire training.

Results

The annual volume of physical training (409-792 h·season^-1) and number of shots fired (1,163-17,328 shots·season^-1) increased from the age of 17 to 28 followed by a subsequent reduction in physical training (range 657-763 h·season^-1) and shots fired (13,275-15,355 shots·season^-1) during the seasons of peak performance at ages 31-33. Maximal oxygen uptake in roller ski skating increased by 10% (62.9-69.2 ml·kg^-1·min^-1) from the age of 22 to 27. The physical training volume was 48% higher (694 ± 60 vs. 468 ± 23 h·season^-1, P = .030), with 175% more shots fired (14,537 ± 1,109 vs. 5,295 ± 3,425 shots·season^-1, P = .016) as a senior athlete than a junior athlete. In the physical training, these differences were mainly explained by higher volumes of LIT (602 ± 56 vs. 392 ± 22 h·season^-1, P = .032) and MIT (34 ± 1 vs. 7 ± 2 h·season^-1, P = .001) but less HIT (27 ± 1 vs. 42 ± 3 h·season^-1, P = .006) as a senior than a junior. In line with this, shooting training as a senior included more shots fired both at rest (5,035 ± 321 vs. 1,197 ± 518 shots·season^-1, P = .011) and during LIT (7,440 ± 619 vs. 2,663 ± 1,975 shots·season^-1, P = .031), while a smaller insignificant difference was observed in the number of shots fired in connection with MIT, HIT, and competitions (2,061 ± 174 vs. 1,435 ± 893 shots·season^-1, P = .149).

Conclusions

This study provides unique insights into the long-term development of physical and shooting training from junior to senior in a world-class female biathlete. The major differences in training characteristics between junior and senior athlete seasons were higher sport-specific volumes of LIT and MIT and less HIT. These differences were accompanied by more shooting training, particularly at rest, and in connection with LIT.